Ingot mold insert mat



Nov. 3, 1959 H. D. STERICK ETAL 2,910,747

INGOT MOLD INSERT MAT Original Filed Oct. 19, 1953 r mmhiil INVEN TOR. HARRISON D. STERIC'K.

F 5 BY WILLIAM E. SCHMERTZ.

ATTO'R N EYS United States Patent INGOT MOLD INSERT MAT Harrison D. Sterick and William E. Schmertz, Pittsburgh, Pa.

Original application October 19, 1953, Serial No. 386,877, now Patent No. 2,807,846, dated October 1, 1957. Divided and this application September 27, 1957, Serial No. 686,722

3 Claims. (Cl. 22-139) This invention relates to mats for insertion in ingot molds, and is a division of our application Serial No. 386,877, filed October 19, 1953, now Patent No. 2,807,846, granted October 1, 1957.

Ingot mold mats are made in a variety of forms, all of which involve the winding of strip metal into a flat coil. Sometimes a single strip is wound upon itself, but ordinarily two or more strips are wound together. ()ne may be corrugated, and one flat, or they may both be flat, and often they are of diflerent widths as disclosed in our application Serial No. 386,877.

The mats generally weigh in the neighborhood of 18 to 20 pounds. The winding begins at the center and the convolutions are formed outwardly from the center. At the periphery of the mat the end of the strip is welded to the outermost convolution beneath it to hold the mat from uncoiling. The mats in use are necessarily roughly handled, and it not infrequently happens that the center of a mat will be pushed up from the plane of the mat into a kind of a cone, whereupon the mat will spring open and be unusable. Various attempts to overcome this difliculty have been attempted, as by welding a strip of metal across the diameter of the mat, but this has not proved satisfactory. According to the present invention a metal strap is put around the mat just to one side of the diameter before the end of the mat is welded and while the mat is still on the winding machine. The ends of this strap are securely locked together, after which the mat is removed from the forming machine and the end of the strip is welded to the outermost convolution in the manner above described. Contrary to expectations the strip being so positioned at one side of the diameter will securely hold the mat from uncoiling or from coning out. This is due to the fact that the forces generated within the mat tending to unwind the mat in the manner of a clock spring unwinding create a tremendous pressure against the ends of the mat while any movement of the outer convolution is in a direction tending to draw the mat toward a diameter thus tending to elongate the strap and make it tighter.

Our invention may be more fully understood by reference to the accompanying drawing in which:

Fig. 1 is a plan view of a mat embodying our invention;

Fig. 2 is a side elevation; and

Fig. 3 is an elevation of the plate on which the mat is formed.

Referring first to Fig. 3, the mat is formed on a rotating plate 2 having a core pin 3 at its center. This core pin 3 may be bifurcated to receive the end of the strip and may be removable or it may be the end of a shaft on which the turntable 2 is mounted. Such a removable pin is shown in our application above referred to. The plate is rotated by power-driven means, and the metal strip is pulled under tension in a manner well understood in the art to wind the strip into a flat coil. According to our invention the turntable 2 has a shallow groove 4 formed across the face of it just to one side of the diameter.

Referring now to Figs. 1 and 2, 5 designates a mat formed of coiled strip having planar side surfaces or faces. It may be formed of strips of different widths as disclosed in our application above referred to, or may be of the form shown in Patent No. 2,453,643 dated November 9, 1948 to William E. Schmertz, or may be otherwise formed of one or more convolutions of strip metal wound upon itself. The outermost end of the coiled strip is designated 6, and it is welded at 7 to the outermost convolution 8 immediately beneath it. Passing around the mat to one side of the diameter is a metal strap 9, this being formed of a band of metal similar to that used in tying bales, or for strapping shipping containers, and the ends are joined together in any suitable fashion, as by crimping, as indicated at It the crimping being done in the usual manner for fastening the ends of baling straps. The band 9 is in the position of a chord of a circle defined by the mat and is positioned to the same side of the diameter of the mat as the outermost end 6 of the strip. The mat is wound under tension on the plate 2 in the manner above described, and when it has reached the desired diameter, the strip from which it is being formed is cut with the end 6 being to the left of the groove 4 in the turntable as viewed in Fig. 3. Before the metal is cut, however, and while it is still under tension, a strip of metal forming the band 9 is slid through the groove 4 under that face of the coil which is adjacent the face of the plate 2, and the ends of the strip so inserted and then brought together and joined at 10 in the manner above indicated. When this has been done the strip is cut. The coil immediately tends to unwind, but it cannot unwind because it expands against the band 9, putting the band under great tension. The end 6 is then welded as at 7 to permanently fasten the end of the strip to the periphery of the mat. The metal in the mat is exerting a continuous force tending to unwind, but this force is resisted by the band 9, and since the band is to one side of the center, the un winding pressure is in a direction which tends to always draw the band toward the diameter of the mat.

A band placed across the diameter will slip oif in the handling of the mat, but a band placed to one side of the diameter in the position of a chord across the circular mat cannot move in a direction to slip oil because if it tends to move in a direction toward the left as viewed in Fig. 1, the expansive forces of the coil tend to hold it against movement, and it cannot move toward the right without stretching.

We claim:

1. An ingot mold insert mat comprising strip metal wound into a coil to form a disk-like body with planar side surfaces and a strap for preventing said body from unwinding in the location of a chord of a circle defined by the mat, said strap passing around the body over both surfaces thereof at a position slightly to one side of the diameter of the mat but sufficiently close to the center to traverse substantially all of the convolutions of the mat, said strap having its ends joined together and forming an elongated loop, the major axis of which is shorter than the diameter of the coil.

2. An ingot mold mat as defined in claim 1 in which the end of the strip metal constituting the coil is welded to the periphery of the coil at a point where the strap is positioned between the welded end of the strip and the center of the disk.

3. The method of forming an igot mold insert mat which comprises winding strip metal under tension into a coil having planar side surfaces, passing a metal band about the coil so formed adjacent to but to one side of the axis about which the coil is formed and securing the ends of the band together, the band forming an elongated loop traversing both faces of the coil in the position of a chord of a circle defined by the coil With the long dimension of the loop being of less length than the diameter of the coil severing the strip from which the coil is formed and Welding the outer end of the coilforming strip to the underlying convolutions of the mat with the weld located at the same side of the center of the mat as the band.

References Cited in the file of this patent UNITED STATES PATENTS Scott Jan. 11, 1916 Adams June 5, 1923 Austin May 23, 1933 Mclntier Mar. 31, 1942 FOREIGN PATENTS Canada Oct. 23, 1951 

